JPH0634563Y2 - Lubricating oil supply device for DOHC type multi-cylinder internal combustion engine - Google Patents

Description

[Detailed Description of the Invention] A. Purpose of the Invention (1) Field of Industrial Application In the present invention, a plurality of cylinders are arranged in series in a cylinder block, and a cylinder head is provided on both sides of each cylinder along the cylinder arrangement direction. A plurality of cams including a low speed cam and a high speed cam correspond to each cylinder while being adjacent to each other on a pair of mutually parallel cam shafts rotatably supported by a cam holder fastened to the cylinder head. A pair of rocker shafts fixedly mounted on the cylinder head and fixedly supported on the cylinder head are provided with a plurality of rocker arms corresponding to the intake valves and the exhaust valves of each cylinder so as to make sliding contact with each cam. In the rocker arm, mutual connection and disconnection can be switched according to the hydraulic pressure in order to change the operation mode of the intake valve and the exhaust valve according to the operating state of the engine. The DOHC type multi-cylinder internal combustion engine forming changeover mechanism is provided a lubricating oil fueling device.

(2) Conventional Technology Conventionally, such an internal combustion engine is known from, for example, JP-A-60-27717 and JP-A-62-121812.

(3) Problems to be Solved by the Invention In such an internal combustion engine, the hydraulic pressure of the connection switching mechanism changes according to the operating state of the engine, and the operation of the connection switching mechanism affects the lubrication oil supply. It is desirable not to affect.

The present invention has been made in view of the above circumstances, and provides a lubricating oil supply device for a DOHC type multi-cylinder internal combustion engine that can supply lubricating oil stably regardless of the operation of the connection switching mechanism and has a simple structure. The purpose is to provide.

B. Configuration of the Invention (1) Means for Solving the Problems According to the present invention, the cylinder head is provided with a low-speed hydraulic pressure supply passage at substantially the central portion along the arrangement direction of each cylinder, and the A high-speed hydraulic pressure supply passage, which is open at one end face along the arrangement direction, is provided independently of the low-speed hydraulic pressure supply passage, and a substantially central cam holder along the arrangement direction of each cylinder has intake and exhaust sides. The sliding contact portion of the cam including at least the low speed cam of the cylinder and the rocker arm, and the branch oil passage communicating with the low speed hydraulic pressure supply passage for supplying oil to the cam journal portion of the cam shaft are distributed to the intake side and the exhaust side. Provided in both rocker shafts are coaxial connection oil supply passages for supplying oil to the connection switching mechanisms and the sliding contact portions of the high speed cam and the rocker arm. The cylinder head is provided with a communication passage communicating with both oil supply passages at a position near one end of the cylinder head and an oil supply port communicating with one of the oil supply passages and opening to one end surface of the cylinder head. A switching valve capable of switching communication and cutoff between the opening of the high-speed hydraulic pressure supply passage and the fuel supply port is attached.

(2) Operation According to the above configuration, the sliding contact portion between each cam including at least the low speed cam and the rocker arm, the oil supply to each cam journal portion, the connection switching mechanism, and the sliding contact portion between the high speed cam and the rocker arm. Since the oil is supplied to each of the cylinders independently of each other, the sliding contact portion between each cam including at least the low speed cam and the rocker arm, and each Lubricating oil is always sufficiently supplied to the cam journal section. Moreover, since the low-speed hydraulic pressure supply passage and the branch oil passage are arranged substantially at the center along the arrangement direction of each cylinder, it is possible to prevent a time lag from occurring in the supply of the lubricating oil to the lubricating portion and to distribute the lubricating oil to each lubricating portion. The pressure loss can be made almost even and the supply amount can be made even. Further, the hydraulic pressure supply switching of the intake and exhaust coupling switching mechanisms can be performed only by attaching a single switching valve to one end surface of the cylinder head, and one low speed and one high speed hydraulic supply passage is provided. Since it may be provided on the cylinder head, the cylinder head can be easily processed.

(3) Embodiment Hereinafter, one embodiment of the present invention will be described with reference to the drawings. First, in FIG. 1 and FIG. 2, this DOHC type multi-cylinder internal combustion engine has four cylinders 2 arranged in series in a cylinder block 1. Combustion chambers 5 are defined between a cylinder head 3 that is provided side by side and is coupled to the upper end of the cylinder block 1, and a piston 4 that is slidably fitted in each cylinder 2. Further, the cylinder head 3 is provided with a pair of intake ports 6 and a pair of exhaust ports 7 in the portion forming the ceiling surface of each combustion chamber 5, and each intake port 6 is opened on one side surface of the cylinder head 3. Connected to the intake port 8, and each exhaust port 7 is connected to an exhaust port 9 opening on the other side surface of the cylinder head 3.

In the portion corresponding to each cylinder 2 of the cylinder head 3,
Guide cylinders 11i and 11e are fitted and fixed to guide a pair of intake valves 10i that can open and close each intake port 6 and a pair of exhaust valves 10e that can open and close each exhaust port 7, respectively. Of the intake valves 10i and the exhaust valves 10e protruding upward from the guide cylinders 11i, 11e of the respective flanges 12i, 12e
And the cylinder head 3, the valve springs 13i and 13e are respectively compressed, and the intake valves 1i and 13e are connected to the intake valves 1 and 13e, respectively.
0i and each exhaust valve 10e are urged upward, that is, in the valve closing direction.

A working chamber 15 is defined between the cylinder head 3 and a head cover 14 connected to the upper end of the cylinder head 3.
In the working chamber 15, intake valves 10i in each cylinder 2 are installed.
An intake valve side valve operating device 17i for opening and closing the engine and an exhaust valve side valve operating device 17e for opening and closing the exhaust valve 10e in each cylinder 2 are housed and arranged. Double valve device 17i, 1
7e has basically the same configuration. In the following description, the intake valve side valve operating device 17i will be described with reference numeral suffixed with i, and the exhaust valve side valve operating device 17e will be referred to. Only the subscript e is attached to the reference numeral for illustration.

Referring to FIGS. 3 and 4 together, the intake valve side valve operating device 17i includes a camshaft 18i that is rotationally driven from a crankshaft (not shown) of the engine at a speed reduction ratio of 1/2, and Cylinder 2
The low speed cams 19i and 20i and the high speed cam 21i respectively provided on the cam shaft 18i, and the cam shaft 18i.
A rocker shaft 22i fixedly arranged in parallel with i, a first drive rocker arm 23i, a second drive rocker arm 24i and a free rocker arm 25i pivotally supported by the rocker shaft 22i corresponding to each cylinder 2, and each cylinder 2 And a connection switching mechanism 26i provided between the rocker arms 23i, 24i, 25i, respectively.

Referring also to FIG. 5, the cam shaft 18i is arranged above the cylinder head 3 so as to be parallel to the arrangement direction of the cylinders 2 and to be rotatable around its axis. That is, the cylinder head 3 is integrally provided with cam support portions 27, 27 at both end portions along the arrangement direction of each cylinder 2, and three cam support portions 28 ... Are provided at positions corresponding to each cylinder 2. Cam holders 29, 29 which are integrally provided respectively and which are respectively fastened on the cam supporting portions 27, 27 at both ends, and 3
Cam holders that are fastened on the two cam supports 28 ...
The cam shaft 18i is rotatably supported around the axis by 30 and the cam supporting portions 27, 27, 28. Moreover, the cam holder 29 is provided independently of each of the intake valve side valve operating device 17i and the exhaust valve side valve operating device 17e, while the cam holder 30 is commonly provided to both valve operating devices 17i and 17e. The cam shaft 18 is provided on the upper surface of each cam support portion 27, 27, 28.
Semi-circular support surface 31 for supporting the outer peripheral surface of the lower half of i, 18e
Each of the cam holders 29, 30 is provided with a semi-circular support surface 32 for supporting the cam shafts 18i, 18e on the outer peripheral surfaces of the upper half portions on the lower surface thereof.

Further, insertion holes 34 for inserting bolts 33 for fastening the cylinder head 3 to the cylinder block 1 are formed in the respective cam support portions 27, 27, 28 ... Up and down one by one at positions corresponding to the cam shafts 18i, 18e. The operation hole 35 for rotating the bolt 33 is provided at an upper position corresponding to the insertion hole 34 while extending upward and downward while opening the upper end to the semicircular support surface 31. To be done.

A cylindrical central block 36 extending vertically is integrally provided on the cylinder head 3 at a portion corresponding to the central portion of each cylinder 2 between the cam support portions 27, 27, 28. 36 and the cam support portions 27, 27, 28 ... On both sides are connected to each other by a support wall 37. Further, the head cover 14 is provided with a cylindrical central block 49 connected to the central block 36. Plug insertion hole 38 in central block 36, 49
And the combustion chamber 5 is inserted in the plug insertion hole 38.
A spark plug 39 is inserted into the interior.

The timing pulley 4 is attached to one end of each of the camshafts 18i, 18e protruding from the cylinder head 3 and the head cover 14.
0, 41 are fixed, and a timing belt 42 for transmitting a driving force from a crank shaft (not shown) is wound around both timing pulleys 40, 41. As a result, both cam shafts 18i and 18e rotate in the same direction.

The low speed cams 19i and 20i are integrated into a position corresponding to the camshaft 18i or each intake valve 10i.
A high speed cam 21i is integrated between 9i and 20i. On the other hand, the rocker shaft 22i is located below the cam shaft 18i,
Each cam support 2 having an axis parallel to the cam shaft 18i
It is fixedly held by 7,27,28 .... The rocker shaft 22i has a first intake valve 10i that is interlocked with and connected to the first intake valve 10i.
The drive rocker arm 23i, a second drive rocker arm 24i that is interlocked and connected to the other intake valve 10i, and a free rocker arm 25i that is arranged between the first and second drive rocker arms 23i and 24i are adjacent to each other and pivot. Supported.

Tappet screws 43i are respectively screwed to the first and second drive rocker arms 23i, 24i so as to be able to advance and retreat, and these tappet screws 43i abut on the upper ends of the corresponding intake valves 10i, whereby both drive rocker arms 23i, 24i is the intake valve 10i
Are linked and linked to each other.

In addition, the free rocker arm 25i uses the lost motion mechanism 44i interposed between the free rocker arm 25i and the cylinder head 3 to drive the high-speed cam 2
It is elastically urged in the direction of sliding contact with 1i. This lost motion mechanism 44i has a bottomed cylindrical guide member 45 fitted into the cylinder head 3 with its closed end facing the cylinder head 3.
And a piston 46 slidably fitted to the guide member 45 and abutting the lower surface of the free rocker arm 25i, and a piston 4 for biasing the piston 46 toward the free rocker arm 25i.
The first and second springs 47 and 48 are provided in series between the 6 and the guide member 45, and the spring constants of the first and second springs 47 and 48 are set to be different from each other.

In FIG. 6, a connection switching mechanism 26i includes a first switching pin 51 that can connect the first drive rocker arm 23i and the free rocker arm 25i, and a second switching pin 51 that can connect the free rocker arm 25i and the second drive rocker arm 24i. 52 and a regulation pin 5 that regulates movement of the first and second switching pins 51, 52
3 and a return spring 54 for urging the pins 51 to 53 toward the disconnecting side.
With.

In the first drive rocker arm 23i, a bottomed first guide hole 55 opened to the free rocker arm 25i side is provided with a rocker shaft 22i.
The first switching pin 51 is slidably fitted in the first guide hole 55, and is disposed between one end of the first switching pin 51 and the closed end of the first guide hole 55. The hydraulic chamber 56 is defined. Moreover, the first drive rocker arm 23i is provided with a passage 57 communicating with the hydraulic chamber 56, the rocker shaft 22i is provided with an oil supply passage 58i, and the oil supply passage 58i is provided in the first drive rocker arm 23i.
It always communicates with the hydraulic chamber 56 via the passage 57 regardless of the rocking state of i.

A guide hole 59 corresponding to the first guide hole 55 is formed in the free rocker arm 25i so as to be parallel to the rocker shaft 22i and between both side surfaces, and one end of the first switching pin 51 abuts against the other end. The second switching pin 52 is slidably fitted in the guide hole 59.

In the second drive rocker arm 24i, a second bottomed guide hole 60 corresponding to the guide hole 59 is opened in the free rocker arm 25i side and is provided in parallel with the rocker shaft 22i.
A disc-shaped restriction pin 53 that abuts the other end of the second switching pin 52 is slidably fitted in the second guide hole 60. Moreover, a guide cylinder 61 is fitted in the closed end of the second guide hole 60, and a shaft portion 62 slidably fitted in the guide cylinder 61 is provided coaxially and integrally with the restriction pin 53 so as to project. It The return spring 54 is a guide tube.
This return spring is inserted between 61 and the regulation pin 53.
The pins 51, 52, 53 are biased toward the hydraulic chamber 56 side by 54.

In the connection switching mechanism 26i, the hydraulic pressure in the hydraulic chamber 56 increases, so that the first switching pin 51 fits into the guide hole 59 and the second switching pin 52 fits into the second guide hole 60.
Each rocker arm 23i, 25i, 24i is connected. Also hydraulic chamber 5
When the hydraulic pressure of 6 becomes low, the spring force of the return spring 54 causes the first switching pin 51 to return to the position where the contact surface between the first switching pin 51 and the second switching pin 52 is made to correspond between the first drive rocker arm 23i and the free rocker arm 25i, and the second switching is performed. Since the pin 52 returns to the position where the contact surface with the restriction pin 53 is made to correspond to between the free rocker arm 25i and the second drive rocker arm 24i, each rocker arm 23i, 25i,
The connected state of 24i is released.

Next, referring to FIG. 7, the oil supply system for the both valve operating devices 17i, 17e will be described. At the discharge port of the oil pump 64 that pumps oil from the oil pan 63, the relief valve 65, the oil filter 66, and the oil Oil gallery via cooler 67
68 is connected, hydraulic pressure is supplied from the oil gallery 68 to the connection switching mechanisms 26i, 26e, and the valve operating devices 17i, 1
Lubricating oil is supplied to each lubrication part of 7e.

The oil gallery 68 has a switching valve for switching the hydraulic pressure passing through a filter 70 provided midway between high and low to supply the oil pressure.
69 is connected, and the oil supply passages 58i, 58e in the rocker shafts 22i, 22e are connected to the oil gallery 68 via the switching valve 69. Moreover, passage forming members 72i, 72e extending in parallel corresponding to the cam shafts 18i, 18e are fastened to the upper surfaces of the cam holders 29, 29, 30 by a plurality of bolts 73, respectively. Moreover, in each of the passage forming members 72i, 72e, the low-speed lubrication passages 74i, 74e closed at both ends and the high-speed lubrication passages 75i, 75e communicating with the oil supply passages 58i, 58e via the throttles 76i, 76e are provided. Are provided in parallel with each other.

An oil passage 77, which branches from the oil gallery 68 on the upstream side of the filter 70 and has a throttle 79 in the middle, is provided so as to extend upward in the cylinder block 1 as shown in FIG. Moreover, the oil passage 77 is provided in the cylinder block 1 at a substantially central portion along the arrangement direction of the cylinders 2. On the other hand, the cam support portion 28 at the substantially central portion along the arrangement direction of the cylinders 2 has a low speed hydraulic supply passage 78 communicating with the oil passage 77.
Is provided, and the supply passage 78 communicates with an annular passage portion 78a that surrounds the bolt 33 and the upper end of the passage portion 78a so that the double valve operating device is connected.
A passage portion 78b extending toward the central portion between 17i and 17e, and a passage portion 78b
And a passage portion 78c communicating with the above and extending upward and opening on the upper surface of the cam support portion 28.

Further, the cam holder 30 at the substantially central portion along the arrangement direction of the cylinders 2 has its lower end communicated with the upper end of the passage portion 78c in the low-speed hydraulic pressure supply passage 78, and has a substantially Y-shape distributed to both valve operating devices 17i, 17e. -Shaped branched oil passage 80 is provided, and the upper end of this branched oil passage 80 communicates with the low speed lubricating passages 74i and 74e, respectively. That is, the passage forming members 72i, 72e have communication holes 81i, 8 for communicating the branch oil passage 80 with the low speed lubricating passages 74i, 74e.
1e is drilled respectively.

Low speed lubrication passages 74i, 74e are for each cam 19i, 19e, 20i, 20e, 21i, 21e
With the rocker arms 23i, 23e, 24i, 24e, 25i, 25e, and the cam journal part 1 of the camshafts 18i, 18e.
It is for supplying lubricating oil to 8i 'and 18e'. Therefore, the low-speed cams 19i, 1
9e, 20i, 20e and high-speed cams 21i, 21e at the positions corresponding to the low-speed lubrication passages 74i, 74e lubricating oil injection holes 82i, 8
2e is drilled, and lubricating oil supply passages 83i, 83e communicating with the low speed lubricating passages 74i, 74e are provided to supply lubricating oil to the cam journal portions 18i ', 18e' of the camshafts 18i, 18e. To be done.

The high-speed lubrication paths 75i, 75e are for supplying lubricating oil to the sliding contact portions between the high-speed cams 21i, 21e and the free rocker arms 25i, 25e, and are not provided on the lower surface of the passage forming members 72i, 72e. High-speed lubrication passages 75i, 75e at positions corresponding to high-speed cams 21i, 21e
Lubricating oil ejection holes 84i, 84e communicating with the above are respectively formed.

By the way, the passage forming members 72i and 72e are connected to the camshafts 18i and 18e.
Is located above the above, and each lubricating oil ejection hole 84i, 84e
A part of the lubricating oil ejected from the engine is laterally scattered according to the rotation of the camshafts 18i and 18e. Moreover, since both camshafts 18i, 18e rotate in the same direction, a part of the lubricating oil ejected from one lubricating oil ejection hole 84i is scattered on the exhaust valve side valve operating device 17e side, The lubricating oil ejected from the other lubricating oil ejection hole 84e is the intake valve side valve operating device 1
A part is scattered toward the side opposite to 7i. Thus, since there are central blocks 36, 49 between the valve operating devices 17i, 17e at the portions corresponding to the lubricating oil ejection holes 84i, 84e, some of the scattered lubricating oil is at the central blocks 36, 49. It reflects and returns to the sliding contact side between the high speed cam 21i and the free rocker arm 25i. Further, a part of the lubricating oil ejected and scattered from the lubricating oil ejection hole 84e hits the side portion of the cylinder head 3 and is reflected and reflected by the high speed cam 21e.
And the free rocker arm 25e is returned to the sliding contact side. However, the distance between the sliding contact portions of the high-speed cam 21i and the free rocker arm 25i and the central blocks 36, 49 is determined by the sliding contact portion of the high-speed cam 21e and the free rocker arm 25e and the cylinder head 3
Is smaller than the distance to the side of the cylinder head 3, and therefore the amount of lubricating oil reflected from the central blocks 36 and 49 and returning to the sliding contact portion of the high speed cam 21i and the free rocker arm 25i is reflected from the side portion of the cylinder head 3. And the amount of lubricating oil returned to the sliding contact portion of the high speed cam 21e and the free rocker arm 25e. Therefore, the diameter of the lubricating oil ejection hole 84i is set smaller than the diameter of the lubricating oil ejection hole 84e, and the amount of lubricating oil ejection from the lubricating oil ejection hole 84i is set smaller than the amount of lubricating oil ejection from the lubricating oil ejection hole 84e. To be done. Further, the degree of throttle of the throttle 76i provided between the oil supply passage 58i and the high speed lubrication passage 75i is set to be smaller than that of the throttle 76e provided between the oil supply passage 58e and the high speed lubrication passage 75e. The amount of lubricating oil supplied to the lubrication passage 75i is set smaller than the amount of lubricating oil supplied to the high speed lubrication passage 75e.

The lubricating oil jet holes 82i, 8 communicating with the low speed lubrication passages 74i, 74e
2e is a member for reflecting the lubricating oil in the direction in which the lubricating oil is scattered by the rotation of the cam shafts 18i, 18e, and a low speed cam.
Since the distances between 19i, 19e, 20i, 20e and the sliding contact portions of the first and second drive rocker arms 23i, 23e, 24i, 24e are substantially the same, the hole diameters are set to be substantially the same.

8 and 9, the cylinder block 1 is provided with an oil passage 85 extending vertically near one end along the arrangement direction of each cylinder 2 independently of the oil passage 77. Channel 85 communicates with oil gallery 68 via filter 70 (see FIG. 7). On the other hand, the oil passage 85 is formed in the cylinder head 3 at one end side along the arrangement direction of each cylinder 2.
Is provided with a high-speed hydraulic pressure supply path 86 communicating with the
Is a passage portion 86a that communicates with the upper end of the oil passage 85 and extends slightly upward, a passage portion 86b that communicates with the upper end of the passage portion 86a and further extends to one end side of the cylinder head 3, and a passage portion 86b. And a passage portion 86c that extends upward and a passage portion 86d that communicates with the upper end of the passage portion 86c and that extends to the rocker shaft 22e side of the exhaust valve side valve operating device 17e, and that communicates with the passage portion 86d. And a passage portion 86e opening at one end surface of the.

Referring also to FIG. 10, in the cylinder head 3,
One end of both rocker shafts 22i, 22e, that is, one end of the rocker shaft 22e on the exhaust side is supported, so that an oil supply port 87 communicating with an oil supply passage 58e in the rocker shaft 22e is opened at one end surface of the cylinder head 3. To be drilled. Further, the cylinder head 3 is provided with a communication passage 88 for communicating the oil supply port 87 with the oil supply passage 58i in the rocker shaft 22i on the intake side.

The switching valve 69 includes an opening, that is, a passage portion 86e to the one end surface of the cylinder head 3 of the high-speed hydraulic pressure supply passage 86, and a fuel filler port 87.
It is attached to one end surface of the cylinder head 3 in order to switch communication and cutoff between the cylinder head 3 and an inlet port 89 communicating with the passage portion 86e and an outlet port 90 communicating with the fuel filler 87. A spool valve 92 is slidably fitted in a housing 91 attached to one end surface.

A cylinder hole 94 whose upper end is closed by a cap 93 is formed in the housing 91, and the spool valve body 92 forms an operating hydraulic chamber 95 with the cap 93 and slides in the cylinder hole 94. Can be freely fitted. Moreover, in the spring chamber 96 formed between the lower portion of the housing 91 and the spool valve body 92, a spring for biasing the spool valve body 92 upward, that is, in the closing direction.
97 is stored. The spool valve body 92 is provided with an annular recess 98 capable of communicating between the inlet port 89 and the outlet port 90, and when the spool valve body 92 is moving upward as shown in FIG. 92 is in a state of blocking between the inlet port 89 and the outlet port 90.

With the housing 91 attached to the end surface of the cylinder head 3, an oil filter 99 is sandwiched between the inlet port 89 and the passage portion 86e of the high-speed hydraulic pressure supply passage 86. Further, the housing 91 is provided with an orifice hole 101 that communicates between the inlet port 89 and the outlet port 90. Therefore, even when the spool valve body 92 is in the closed position, the inlet port 89 and the outlet port 90 are communicated with each other through the orifice hole 101, and the hydraulic pressure throttled by the orifice hole 101 is changed to the outlet port 9
It is supplied from 0 to the fuel filler port 87.

Further, the housing 91 is provided with a bypass port 102 which communicates with the outlet port 90 through the annular recess 98 only when the spool valve body 92 is in the closed position, and the bypass port 102 communicates with the upper portion in the cylinder head 3. . Further, the spool valve body 92 is provided with an orifice hole 103 for communicating the inlet port 89 with the spring chamber 96 regardless of the position of the spool valve body 92. In addition, a through hole 104 for communicating the spring chamber 96 with the cylinder head 3 is formed in the lower portion of the housing 91, and the oil that has flowed into the spring chamber 96 through the orifice hole 103 flows from the through hole 104 into the cylinder head 3. Returned inside. As a result, dust and the like attached to the spring 97 are washed away by the oil, so that the dust and the like are prevented from adversely affecting the expansion and contraction operation of the spring 97.

The housing 91 has a conduit 10 that is in constant communication with the inlet port 89.
5 is connected, and this conduit 105 is connected to a conduit 107 via a solenoid valve 106. Moreover, the conduit 107 is connected to the connection hole 108 formed in the cap 93. Therefore, when the solenoid valve 106 is opened, the hydraulic pressure is supplied to the hydraulic pressure chamber 95, and the hydraulic pressure of the hydraulic pressure introduced into the hydraulic pressure chamber 95 drives the spool valve body 92 in the valve opening direction.

A leak jet 109 communicating with an intermediate portion of the pipe 107 is bored in the housing 91, and the leak jet 109 communicates with an upper portion in the cylinder head 3. The leak jet 109 serves to release the hydraulic pressure remaining in the conduit 107 when the solenoid valve 106 is closed.

Further, the housing 91 includes an outlet port 90, that is, an oil supply passage.
A pressure detector 110 for detecting the oil pressures of 58i and 58e is attached, and this pressure detector 110 functions to detect whether or not the switching valve 69 is operating normally.

In FIG. 11, the passage forming member 72 is provided on the other end side of the cylinder head 3, that is, on the side opposite to the mounting position of the switching valve 69.
At the end of i, 72e, a communication hole leading to the high speed lubrication path 75i, 75e
111i, 111e are formed by opening downward, and the communication hole 111 is formed on the upper surface of the cam holder 29 between the passage forming members 72i, 72e.
A pair of grooves are provided to form passages 112i, 112e communicating with i, 111e. Further, communication holes 113i, 113e communicating with the oil supply channels 58i, 58e are formed at the ends of the rocker shafts 22i, 22e, and a passage 114i communicated with these communication holes 113i, 113e is formed in the cylinder head 3. 114e and the passages 112i, 112e communicate with each other via diaphragms 76i, 76e formed in the cam holder 29. Therefore, the oil supplied to the oil supply passages 58i and 58e is
It will be supplied to the high-speed lubrication passages 75i, 75e via 6i, 76e.

Explaining the operation of this embodiment, the low speed lubrication passages 74i, 74e are provided with an oil passage 77, a low speed hydraulic pressure supply passage 78 and a branch oil passage 80 which are independent of the connection switching mechanisms 26i, 26e. Since the lubricating oil is supplied, even if the hydraulic pressure is controlled by the switching valve 69 to operate the connection switching mechanisms 26i, 26e, a constant hydraulic pressure can always be supplied regardless of that, and therefore the low speed cam 19i , 19e, 20i, 20e and each drive rocker arm 23
i, 23e, 24i, 24e sliding contact, high-speed cams 21i, 21e and free rocker arms 25i, 25e sliding contact, and camshaft 1
Lubricating oil can be supplied to the cam journal portions 18i ', 18e' of 8i, 18e at a stable pressure.

Moreover, the oil passage 77, the low speed hydraulic pressure supply passage 78 and the branch oil passage 80
Is disposed at a substantially central portion along the arrangement direction of each cylinder 2, so that the distribution pressure loss of the lubricating oil to the lubricating oil ejection holes 82i, 82e and the lubricating oil supply passages 83i, 83e is made substantially constant. The amount of lubricating oil can be made almost equal.

By switching the connection switching mechanisms 26i, 26e, the intake valves 10i
When the exhaust valves 10e are set to the high speed operation mode, the switching valve 69 is opened as shown in FIG. That is, the solenoid valve 106 is opened to supply hydraulic pressure to the operating hydraulic chamber 95, whereby the spool valve body 92 is operated to open, and the oil supply passage 58i,
When the hydraulic pressure is supplied to 58e and the hydraulic pressure is supplied to the hydraulic chamber 56, the connection switching mechanisms 26i and 26e are connected to each other, and the intake valve 10i and the exhaust valve 10e are opened / closed in a high-speed operation mode.

In this high-speed operation mode, the lubricating oil supplied to the high-speed lubrication passage 75i is ejected from the lubricating oil ejection holes 84i, 84e, and particularly the high-speed cams 21i, 21e and the free rocker arm 2 where the surface pressure becomes large.
It is possible to sufficiently lubricate the sliding contact portion with the 5i and 25e.
Moreover, depending on the distance between the member that reflects the lubricating oil scattered in accordance with the rotation of the cam shafts 18i and 18e and the sliding contact portion of the high speed cams 21i and 21e and the free rocker arms 25i and 25e, the lubricating oil ejection hole 84i , 84e, and set the aperture of 7
Since the apertures of 6i and 76e are set, it is possible to make the amounts of lubricating oil supplied to the respective sliding portions substantially equal.

By the way, when the switching valve 69 is switched to switch from the low speed operating mode to the high speed operating mode, there is a slight time lag until the hydraulic pressure of the high speed lubrication passages 75i, 75e increases due to the throttles 76i, 76e. There is some time delay until the lubricating oil is ejected from the ejection holes 84i, 84e. However, since the lubricating oil ejection holes 82i, 82e leading to the low speed lubrication passages 74i, 74e are also arranged at the positions corresponding to the sliding contact portions between the high speed cams 21i, 21e and the free rocker arms 25i, 25e, Even if there is a slight time delay as described above, there is no shortage of lubricating oil at the sliding contact portions of the high speed cams 21i, 21e and the free rocker arms 25i, 25e. In addition, each pin 51 in the connection switching mechanism 26i, 26e,
When the switching valve 69 is closed and the low speed operation mode is generated while 52 and 53 are locked, the high speed cams 21i and 21e
And the surface pressure of the sliding contact portions of the free rocker arms 25i, 25e increases as in the high speed operation mode, but at this time as well, from the lubricating oil ejection holes 82i, 82e leading to the low speed lubricating passages 74i, 74e to the high speed cam 21i. , 21e and the free rocker arms 25i, 25e are sprayed with the lubricating oil, so that sufficient lubrication can be performed.

When switching the opening / closing operation mode of the intake valve 10i and the exhaust valve 10e from the high speed operation mode to the low speed operation mode, the solenoid valve 106 is closed. When the solenoid valve 106 is closed,
The hydraulic pressure in the pipeline 107 is released from the leak jet 109, the hydraulic pressure in the working hydraulic chamber 95 is promptly released, and the switching valve 69 is promptly closed accordingly. Moreover, when the switching valve 69 is closed, the hydraulic pressure in the oil supply passages 58i and 58e is changed to the bypass port 102.
Is released into the cylinder head 3 by the oil supply passage 58.
i, 58e, that is, the hydraulic chamber 56 in each connection switching mechanism 26i, 26e
The hydraulic pressure of # 2 becomes low quickly, and the switching response from the high speed operating mode to the low speed operating mode is improved.

In such a lubricating oil supply device, a low speed hydraulic supply passage
Since only one 78 and the high-speed hydraulic pressure supply path 86 need to be provided for each cylinder head 3, machining of the cylinder head 3 becomes extremely easy. Moreover, since the switching valve 69 is mounted on the one end surface of the cylinder head 3, the mounting structure is simple. Further, the oil supply passages 58i, 58e are connected to the connection switching mechanism 26i, 2
Since it is commonly used to lubricate 6e and lubricate high-speed lubrication passages 75i and 75e, it is not necessary to separately provide a lubrication conduit or a separate lubrication passage in cylinder head 3. It is possible to efficiently refuel while avoiding an increase in the number of parts and an increase in the number of processing steps.

C. Effect of the Invention As described above, according to the present invention, the cylinder head is provided with the low-speed hydraulic supply passage in the substantially central portion along the arrangement direction of each cylinder, and one end surface along the arrangement direction of each cylinder. A high-speed hydraulic pressure supply passage that opens to the lower side is provided independently of the low-speed hydraulic pressure supply passage, and at least the low-speed cams of the intake-side and exhaust-side cylinders are provided in the cam holder substantially in the center along the arrangement direction of the cylinders. A sliding contact portion between the cam and the rocker arm, and a branch oil passage communicating with the low speed hydraulic pressure supply passage for supplying oil to the cam journal portion of the cam shaft are provided separately for the intake side and the exhaust side. An oil supply passage is coaxially provided in the cylinder to supply oil to the sliding contact parts of the connection switching mechanism and the high-speed cam and rocker arm. The rear head is provided with a communication passage that communicates both oil supply passages, and is also provided with an oil supply opening that communicates with one of the oil supply passages and opens at one end face of the cylinder head. Since a switching valve that can switch between communication and cutoff between the road opening and the oil supply port is installed, the operation of the connection switching mechanism is affected by the sliding contact between the cam including the low speed cam and the rocker arm, and the cam journal. Without this, the lubricating oil can be stably supplied, and the amount of oil supplied to each lubricating portion can be made substantially equal. Also, by simply attaching a single switching valve to the cylinder head, it is possible to switch the connection switching mechanism for intake and exhaust, and refueling the sliding contact part between the high speed cam and the rocker arm according to the operating condition of the engine. Since only one low speed hydraulic supply path and one high speed hydraulic supply path are drilled, the cylinder head can be easily machined. Furthermore, since the oil supply passage is used for both the connection switching mechanism and the high speed lubrication passage, there is no need to provide a separate oil supply pipe line or a separate cylinder head oil supply passage. Therefore, it is possible to avoid an increase in the number of parts and an increase in processing man-hours.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention. FIG. 1 is a longitudinal sectional view of an essential part of an internal combustion engine, which is a sectional view taken along the line I--I of FIG. 2, and FIG. 2 is taken along the line II--II of FIG. A view from the direction of the arrow, FIG. 3 is III of FIG.
-III line sectional view, FIG. 4 is a IV-IV line sectional view of FIG. 1, FIG. 5 is a VV line sectional view of FIG. 2, and FIG. 6 is a transverse sectional view for showing a connection switching mechanism. , FIG. 7 is a diagram showing a refueling system, FIG. 8 is a view taken along the line VIII-VIII of FIG. 2, and FIG. 9 is a view of FIG.
IX-IX line sectional view, FIG. 10 is an enlarged sectional view taken along line XX of FIG. 8 when the switching valve is closed, FIG. 11 is a sectional view taken along line XI-XI of FIG. 2, and FIG. FIG. 11 is a sectional view corresponding to FIG. 10 when the switching valve is opened. 1 ... Cylinder block, 2 ... Cylinder, 3 ... Cylinder head, 10i ... Intake valve, 10e ... Exhaust valve, 18i, 18e
…… Cam shaft, 18i ′, 18e ′ …… Cam journal part, 19i, 19e, 20i, 20e …… Low speed cam, 21i, 21e …… High speed cam, 22i, 22e …… Rocker shaft, 23i, 23e, 24i, 24
e, 25i, 25e ...... Rocker arm, 26i, 26e ...... Connection switching mechanism, 29,30 ...... Cam holder, 58i, 58e ...... Lubrication passage, 69 ......
Switching valve, 78 ... Low speed hydraulic supply path, 80 ... Branching oil path, 86
...... High-speed hydraulic supply path, 87 ...... Filling port, 88 ...... Communication path

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location F02D 13/02 G 7049-3G F02F 1/24 R 8503-3G

Claims (1)

[Scope of utility model registration request] 1. A plurality of cylinders are arranged in series in a cylinder block, and are mutually rotatably supported by cylinder heads and cam holders fastened to the cylinder heads on both sides of each cylinder along the cylinder arrangement direction. A pair of rocker shafts in which a plurality of cams including a low speed cam and a high speed cam are fixedly mounted on a pair of parallel cam shafts so as to correspond to each cylinder while being adjacent to each other, and are fixedly supported by a cylinder head. Is supported by a plurality of rocker arms corresponding to the intake valves and exhaust valves of each cylinder so as to be in sliding contact with the cams, and these rocker arms have operating modes of the intake valves and the exhaust valves according to the operating state of the engine. Lubrication oil supply for a DOHC type multi-cylinder internal combustion engine that is equipped with a connection switching mechanism that can switch connection and disconnection according to the oil pressure in order to change the In the device, the cylinder head is provided with a low-speed hydraulic pressure supply passage in the substantially central portion along the arrangement direction of each cylinder, and a high-speed hydraulic supply passage opening at one end face along the arrangement direction of each cylinder is used for the low-speed hydraulic pressure. The cam holder, which is provided independently of the supply path and extends substantially in the center of the cylinder along the direction of arrangement, has a sliding contact portion between the cam including at least the low speed cam of each cylinder on the intake side and the exhaust side, and the rocker arm, and A branch oil passage that communicates with the low-speed hydraulic supply passage for supplying oil to the cam journal portion of the camshaft is provided separately for the intake side and the exhaust side. Oil supply passages are provided coaxially to lubricate the sliding contact parts of the cam and rocker arm, and both oil supply passages are provided on the cylinder head near one end along the arrangement direction of each cylinder. A communication passage is provided and a fuel supply port communicating with one of the fuel supply passages and opening at one end face of the cylinder head is provided. At one end face of the cylinder head, the opening and the fuel supply port of the high-speed hydraulic pressure supply passage are provided. A lubricating oil supply system for a DOHC type multi-cylinder internal combustion engine, which is equipped with a switching valve capable of switching between communication and cutoff.